xtabond2 chlngdp gdpcap ifi edu cpi def period*, gmm(l.ifi gdp cpi def, lag(1 2)) iv(edu period*) robust noconstant

xtabond2 chlngdp gdpcap ifi edu cpi def open period*, gmm(l.ifi gdp cpi def l.open, lag(1 2)) iv(edu period*) robust noconstant

xtabond2 chlngdp gdpcap ifi edu cpi def open dpop period*, gmm(l.ifi gdp cpi def l.open, lag(1 2)) iv(edu dpop period*) robust noconstant
